You can leave your jumper cables and bulky jump starter machines at home. The Porta-Jump makes reviving your car’s dead battery a snap. Simply connect the device to your car’s cigarette lighter and it’ll charge the battery in about 10 minutes — all while you stay inside your car. No need to stand outside along side of the road or out in the rain. It’s safe and easy to use. Unlike other battery boosters that you eventually throw way, the Porta-Jump recharges itself as you drive your car, so you can use it over and over again. It can easily charge any battery up to 12V. It has a built-in “smart chip” that can detect whether or not the battery you intend on “boosting” will accept a charge.
It measures about 3 x 3 x 2.5 inches and comes in a nylon pouch so you can stash it safely in your glove box. It costs a cheap $20 at JCWhitney. Not bad.